The science of correspondences is Swedenborg's central technical claim and the reason his theology is unlike anything else in the eighteenth century. He held that the natural world exists from and answers to the spiritual world in a fixed relation, that the ancient churches knew this code, that it was lost, and that it had been restored to him. The Arcana Caelestia, published in eight quarto volumes in London between 1749 and 1756, works through Genesis and Exodus verse by verse decoding them on this system, with reports of the spiritual world inserted between chapters. Not every book of the Bible has an internal sense on his account — he excluded much of the Pauline epistles and several Old Testament books from the Word proper, which is itself a considerable claim. The system's appeal to writers has been out of all proportion to the church's size: Blake, Balzac, Emerson, Baudelaire, Yeats, Borges and Helen Keller all read him, and Emerson put him among his Representative Men.